Curcumin complexed in a new PAMAM dendrimer to increase stability and solubility

Dendrimers are one of the most promising innovative polymeric nanocarrier for different bioactives [1]. In continuing our studies on the development of innovative nanocarriers with curcumin, a very key natural product from turmeric with numerous biological activities but low bioavailability [2], we now report on the development and optimization of a new PAMAM dendrimer. Dendrimers are core-shell nanostructures with precise architecture and low polydispersity, which are synthesized in a layer-by-layer fashion (“generation”) around a core unit, resulting in high level of control over size, branching points and surface functionality. The new PAMAM dendrimer was synthesized through divergent method, using benzylamine and methylacrylate, followed by the synthesis of the amide with ethylendiamine and finally a Michael addition with methylacrylate [1]. Size was 176.7 ± 7.3nm, a Pd was 0.33 ± 0.06. According to TEM, globular shape dendrimer aggregates of 96.66nm are present. Curcumin complexation did not affect the structure of dendrimers. Encapsulation efficiency and loading capacity were very satisfactory, 88% and 21%, respectively. Stability of curcumin complexed with the dendrimer was evaluated by HPLC and resulted satisfactory during three months analysis. The release studies of curcumin from dendrimer showed a slow release profile, which is essential for a sustained and prolonged activity. Dendrimer did not show cytotoxicity in MCF-7 cells while curcumin had an IC50 of 3 × 10-5 M. Studies with the complexed formulation are ongoing.